The method of the present invention provides a variety of vehicle performance characteristics depending on the mode of operation. A first routine is initiated to provide an optimal balance of powertrain responsiveness and fuel economy for any given combination of vehicle speed and deceleration rate. The first routine may, according to a preferred embodiment, include a plurality of routines that are each configured to provide an optimal balance of powertrain responsiveness and fuel economy within a predefined range of vehicle speeds and deceleration rates. A second routine is initiated if said deceleration rate is within a predefined range. The second routine includes running the electric motor/generator while the hybrid vehicle is being stopped in order to control the driveline lash and thereby minimize disturbances during a subsequent engine re-start.
|
5. A method for controlling a powertrain of a hybrid vehicle, said powertrain including an engine, a transmission, and an electric motor/generator, such that the engine and the electric motor/generator are operatively connected to the transmission via a driveline, said method comprising:
providing a torque converter disposed between the engine and the transmission, said torque converter including a torque converter clutch that is actuatable to lock-up the torque converter such that energy is transferable therethrough with minimal loss;
monitoring vehicle speed;
monitoring vehicle deceleration rate; and
initiating a routine if said deceleration rate is within a predefined range, said routine including:
determining whether the vehicle speed is below a predefined threshold speed;
pre-loading the driveline by running the electric motor/generator in a manner configured to control driveline lash while the hybrid vehicle is in the process of being stopped, if the vehicle speed is below the predefined threshold speed, such that disturbances during a subsequent engine re-start are minimized; and
wherein said initiating a routine includes releasing the torque converter clutch if the vehicle speed is below the predefined threshold speed.
1. A method for controlling a powertrain of a hybrid vehicle, said powertrain including an engine, a transmission, and an electric motor/generator, such that the engine and the electric motor/generator are operatively connected to the transmission via a driveline, said method comprising:
monitoring vehicle speed;
monitoring vehicle deceleration rate;
initiating a first routine configured to provide an optimal balance of powertrain responsiveness and fuel economy for any given combination of vehicle speed and deceleration rate;
initiating a second routine if said deceleration rate is within a predefined range, said second routine including pre-loading the driveline by running the electric motor/generator while the hybrid vehicle is in the process of being stopped for a predetermined amount of time after the hybrid vehicle has reached a predetermined speed to control driveline lash, and disturbances during a subsequent engine re-start are thereby minimized;
providing a torque converter disposed between the engine and the transmission, said torque converter including a torque converter clutch that is actuatable to lock-up the torque converter such that energy is transferable therethrough with minimal loss; and
wherein said initiating a first routine includes transferring fuel to the engine at a first predetermined time and releasing the torque converter clutch, thereby interrupting the transfer of a torque spike from the engine to the transmission during the subsequent engine re-start.
2. The method of
3. The method of
4. The method of
6. The method of
7. The method of
8. The method of
|
This application claims the benefit of U.S. Provisional Application 60/685,814, filed May 31, 2005, which is hereby incorporated by reference in its entirety.
The present invention relates to a method for hybrid vehicle powertrain control.
A hybrid electric vehicle may be powered alternatively or simultaneously by an internal combustion engine and an electric motor/generator to maximize fuel economy. To propel the vehicle from a stopped position, the motor/generator can draw electrical energy from a battery to turn the engine crankshaft. As vehicle speed increases, fuel and spark are delivered to initiate engine operation. At a certain vehicle speed range, the motor/generator may operate as a generator driven by the engine crankshaft to recharge the battery and to supply electrical power to auxiliary vehicle devices such as fans, radios, etc.
The method of the present invention is configured to provide a variety of vehicle performance characteristics depending on the mode of operation. For example, the present invention is configured to provide maximum powertrain responsiveness during an aggressive driving mode, conventional creep torque during low deceleration “parking lot mode”, and an optimal balance of powertrain responsiveness and fuel economy during a conventional driving mode. The present invention is additionally adapted to restart the engine of a hybrid electric vehicle with minimal disturbance.
The method for controlling a hybrid vehicle powertrain includes monitoring vehicle speed and vehicle deceleration rate. A first routine is initiated to provide an optimal balance of powertrain responsiveness and fuel economy for any given combination of vehicle speed and deceleration rate. The first routine may, according to a preferred embodiment, include a plurality of routines that are each configured to provide an optimal balance of powertrain responsiveness and fuel economy within a predefined range of vehicle speeds and deceleration rates. A second routine is initiated if said deceleration rate is within a predefined range. The second routine includes controlling the electric motor/generator while the hybrid vehicle is being stopped in order to control driveline lash and thereby minimize disturbances during a subsequent engine re-start.
The first routine may include transferring fuel to the engine at a first predetermined time and releasing a torque converter clutch to interrupt the transfer of a torque spike from the engine to the transmission during a subsequent engine re-start.
The second routine may include running the electric motor/generator for a predetermined amount of time after the hybrid vehicle has reached a predetermined speed to control driveline lash and thereby minimize disturbances during a subsequent engine re-start.
The method for controlling a hybrid vehicle powertrain may also include shutting off the engine after the completion of the first routine or the second routine.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings, wherein like reference numbers refer to like components,
The electric motor/generator 14 of the hybrid vehicle 10 is controlled by an electric motor/generator controller 18. The electric motor/generator 14 is operatively connected to the engine 12 such that the motor/generator 14 selectively operates as a starter (by supplying a cranking torque to the engine 12), and as a generator (by receiving rotational energy from the engine 12 and converting it to electrical energy for recharging a battery 19).
The transmission 16 of the vehicle drive system is a well-known device that includes a plurality of gear sets and friction devices (not shown) operable to provide a number of drive speed ratios between the engine 12 and vehicle drive wheels (not shown). A powertrain control module (PCM) 20 controls the operation of the engine 12, transmission 16, and motor/generator controller 18. It should be appreciated that according to an alternate embodiment, the single PCM 20 shown may be replaced by alternate or additional control modules such as, for example, an engine control module and/or a transmission control module.
The method of the present invention is configured to provide a variety of different vehicle performance characteristics depending on the mode of operation. For example, the present invention is configured to provide maximum powertrain 17 responsiveness during an aggressive driving mode, conventional creep torque during low deceleration “parking lot mode”, and an optimal balance of driveability and fuel economy during a conventional driving mode. For purposes of the present invention, “creep torque” is defined as a minimal amount of torque sufficient to drive the vehicle 10 slowly. “Powertrain responsiveness” is defined as the time required for the vehicle 10 to respond to an acceleration command.
For purposes of the present invention, four basic vehicle operation modes have been defined including: abrupt deceleration rate in a high vehicle speed band or range, abrupt deceleration rate in a low vehicle speed band or range, normal deceleration rate in the low vehicle speed band, and slow deceleration rate in the low vehicle speed band. “Normal deceleration” may be defined, for example, as that within the range of 1.5 and 20 mph/second. Accordingly, “abrupt deceleration” includes any deceleration rate above 20 mph/second, and similarly “slow deceleration” includes any deceleration rate below 1.5 mph/second. The “high vehicle speed band” is preferably defined between 20 and 25 mph, and the low vehicle speed band is between 14 and 19 mph. It should be appreciated that additional and/or alternate vehicle operation modes may be defined, and that the exemplary definitions for the deceleration rates and speed bands may vary according to alternate embodiments.
Referring to
The solid line labeled “normal deceleration” represents a normal deceleration rate. The dashed line labeled “abrupt hi” represents an abrupt deceleration initiated in the high speed band. The dashed line labeled “abrupt low” represents an abrupt deceleration initiated in the low speed band. The dotted line labeled “slow low” represents a slow deceleration initiated in the low speed band. Time T1 represents the time at which the “abrupt hi” curve reaches vehicle speed V2′, time T2 represents the time at which the “abrupt lo” curve reaches vehicle speed V4′, and time T3 represents the time at which the “slow low” curve reaches the vehicle speed V4′.
As shown in
According to a preferred embodiment of the present invention, at step 56 the PCM 20 is adapted cut off the transfer of fuel to the fuel injectors 13 (shown in
At step 58, the algorithm 50 is configured to determine whether the current vehicle speed Vcurrent is within the low speed band defined between V3 and V4 (shown in
At step 62, the algorithm 50 is configured to determine whether the current vehicle speed Vcurrent is within the low speed band defined between V3 and V4 (shown in
Referring to
At step 72, the algorithm 50 determines whether the current vehicle speed Vcurrent is zero (i.e., the vehicle 10 is completely stopped), and a first timer (Timer1) has expired. Timer1 is preferably implemented to ensure that engine rotation is enabled for a predetermined amount of time (e.g., 0.9 seconds) after the vehicle 10 (shown in
Referring to
At step 78, the algorithm 50 determines whether the current vehicle speed Vcurrent is zero (i.e., the vehicle 10 is completely stopped), and a second timer (Timer2) has expired. Timer2 is preferably implemented to ensure that engine rotation is enabled for a predetermined amount of time (e.g., 0.6 seconds) after the vehicle 10 (shown in
Referring to
At step 84, the algorithm 50 determines whether the current vehicle speed Vcurrent is zero (i.e., the vehicle 10 is completely stopped), and a third timer (Timer3) has expired. Timer3 is preferably implemented to ensure that engine rotation is enabled for a predetermined amount of time (e.g., 0.4 seconds) after the vehicle 10 comes to a stop to minimize driveline lash, and to provide responsive driveability in case the operator chooses to accelerate. If Vcurrent is zero and Timer3 has expired, step 64 of the algorithm 50 is completed. If Vcurrent is not zero or Timer3 has not expired, the algorithm 50 returns to step 80.
Referring to
At step 90, the algorithm 50 (shown in
Referring again to
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
Tamai, Goro, Aldrich, III, William L., Bhattarai, Birendra P., Crites, Donald D., Hoang, Tony T.
Patent | Priority | Assignee | Title |
8046142, | Nov 04 2008 | GM Global Technology Operations LLC | Apparatus and method for determining driveline lash estimate |
8340888, | May 06 2010 | GM Global Technology Operations LLC | System and method for reducing powertrain disturbances based on system energy |
8453620, | May 25 2010 | GM Global Technology Operations LLC | Systems and methods for improved engine start-stop response |
8818594, | Jun 09 2011 | Dr. Ing. h.c. F. Porsche Aktiengesellschaft | Method for operating a hybrid vehicle |
9246417, | Aug 26 2014 | Ford Global Technologies, LLC. | System and method for regenerative braking |
Patent | Priority | Assignee | Title |
4487303, | Dec 27 1982 | Ford Motor Company | Automatic transmission start-up clutch control system |
4757886, | Jan 20 1987 | FORD GLOBAL TECHNOLOGIES, INC A MICHIGAN CORPORATION | Transmission clutch closed loop slip controller and method |
5325029, | Nov 30 1992 | Eaton Corporation | Method of controlling an automated mechanical transmission shift mechanism |
5469948, | Jan 31 1994 | Eaton Corporation | Clutch ball ramp actuator with coast lock |
5481170, | Aug 11 1993 | Eaton Corporation | Method and apparatus for controlling shift force in an automated mechanical transmission |
6176808, | Jul 15 1999 | Ford Global Technologies, Inc. | Hybrid vehicle powertrain and control therefor |
6307277, | Apr 18 2000 | GM Global Technology Operations LLC | Apparatus and method for a torque and fuel control system for a hybrid vehicle |
6371739, | Jan 22 1999 | Matsushita Electric Industrial Co., Ltd. | Method and apparatus for applying pre-load to the bearing structure of a drive shaft that is directly driven by an electric motor |
6574535, | May 31 2000 | GM Global Technology Operations LLC | Apparatus and method for active driveline damping with clunk control |
6645109, | Mar 27 2001 | NEW VENTURE GEAR, INC | Two-speed transfer case with ball-ramp clutch and single motor activator/shift system |
20020093202, | |||
20020117338, | |||
20020137597, | |||
20020179047, | |||
20050054482, | |||
20050250618, | |||
20060266567, |
Date | Maintenance Fee Events |
Nov 23 2010 | ASPN: Payor Number Assigned. |
Apr 02 2014 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Apr 19 2018 | M1552: Payment of Maintenance Fee, 8th Year, Large Entity. |
Apr 21 2022 | M1553: Payment of Maintenance Fee, 12th Year, Large Entity. |
Date | Maintenance Schedule |
Nov 02 2013 | 4 years fee payment window open |
May 02 2014 | 6 months grace period start (w surcharge) |
Nov 02 2014 | patent expiry (for year 4) |
Nov 02 2016 | 2 years to revive unintentionally abandoned end. (for year 4) |
Nov 02 2017 | 8 years fee payment window open |
May 02 2018 | 6 months grace period start (w surcharge) |
Nov 02 2018 | patent expiry (for year 8) |
Nov 02 2020 | 2 years to revive unintentionally abandoned end. (for year 8) |
Nov 02 2021 | 12 years fee payment window open |
May 02 2022 | 6 months grace period start (w surcharge) |
Nov 02 2022 | patent expiry (for year 12) |
Nov 02 2024 | 2 years to revive unintentionally abandoned end. (for year 12) |